7. Driver Unit

Figure 7.1: The Driver unit directory tree.

The Driver unit controls the initialization and evolution of FLASH simulations. In addition, at the highest level, the Driver unit organizes the interaction between units. Initialization can be from scratch or from a stored checkpoint file. For advancing the solution, the drivers can use either an operator-splitting technique adapted to directionally split physics operators like split Hydro (Split), or a more generic “Unsplit” implementation. The Driver unit also calls the IO unit at the end of every timestep to produce checkpoint files, plot files, or other output.